Electromagnetic Actuator Control for Expansion Valve Pressure Regulation
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Solution Overview
Problem
Existing electromagnetic actuators used in regulators cannot accurately control fluid flow from a given valve position, limiting their ability to regulate pressure effectively.
Innovation Solution
The proposed solution involves an electronic control regulator with a valve actuated by an electromagnetic actuator, where a control calculator converges the valve position towards a setpoint using a first control law, and adjusts the pressure to a setpoint using a second control law based on models of fluid flow and pressure dynamics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a determined voltage is applied to the electromagnetic actuator to produce a given electromagnetic force, then the valve position can be precisely controlled, but the flow rate cannot be precisely controlled
Solution Approach 1:
The control computer receives feedback from both the position sensor (providing valve position information) and the flow sensor (providing flow rate information). This dual feedback mechanism allows the system to simultaneously monitor and control both valve position and flow rate, resolving the contradiction by using feedback from both parameters to adjust the electromagnetic actuator voltage accordingly
Solution Approach 2:
The system changes the control parameters from solely voltage-based control to a combined position and flow rate control approach. By introducing flow rate as an additional control parameter alongside valve position, the system can adjust the electromagnetic actuator voltage to achieve precise flow rate control while maintaining awareness of valve position, thus resolving the limitation of voltage-only control
2Device complexity
If a simple voltage control law is used for the electromagnetic actuator, then the control system is simple, but precise flow rate control cannot be achieved
Solution Approach 1:
The control computer implements a feedback control algorithm that receives signals from both the position sensor and flow sensor. This feedback mechanism enables the system to automatically adjust the electromagnetic actuator voltage based on the difference between actual and desired flow rates, achieving precise flow rate control without requiring complex manual calculations or multiple control laws
Solution Approach 2:
The control system performs self-adjustment by continuously monitoring both valve position and flow rate, then automatically modifying the electromagnetic actuator voltage to eliminate any deviation from the desired flow rate. This self-service capability allows the system to maintain precise flow rate control while keeping the control logic relatively simple, as the system autonomously handles the coordination between position and flow rate parameters
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for precise control of fluid flow and pressure regulation, enabling the regulator to achieve a specific flow rate from a given valve position, thereby improving the efficiency and accuracy of pressure control.
Implementation Method 1
control the actuator according to a determined voltage to produce a given electromagnetic force and thus obtain precise positioning
Implementation Method 2
a variable reluctance electromagnetic actuator comprising a fixed ferromagnetic armature, a magnetization coil secured to this armature and a moving assembly
Data Source
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AI summary
The invention relates to an electronically controlled expansion valve (1) having a controlled valve (10) inserted between a source (2) at a first pressure (P1) and an outlet (3) at a second pressure (P2), a pressure sensor (9) designed to measure the second pressure and a computer (7) designed to control the valve (10) so as to bring about a pressure drop between the source and the outlet, making it possible to feedback-control the second pressure (P2) to a setpoint pressure (Pref), the valve (10) comprising an actuator (14) for driving a member (13) for restricting a passage section (11) for the fluid, between the source (2) and the fluid outlet (3), so as to vary the passage section, the restriction (11) being implemented by means of a passage orifice (12) for the fluid and a shut-off member (13) placed on the axis of the orifice and designed such that an axial movement of the shut-off member (13) brings about a variation in the passage section (11) for the fluid, the expansion valve (1) having a position sensor (19) for the shut-off member (13), characterized in that the computer (7) uses a first control law (LC1) to make the position (X1) of the shut-off member (13) converge towards a setpoint position (Yr), the setpoint position (Yr) being determined via a second control layer (LC2) for making the second pressure (P2) converge towards the setpoint pressure (Pref), on the basis of a model (MD) of a flow rate (Dcol) through the expansion valve (1), the second control law (LC2) also being determined on the basis of a model (MP) of the second pressure (P2) as a function of the flow rate (Dcol) through the expansion valve and a consumption flow rate (Ds) downstream of the fluid outlet (3).